How to delete cache in redis

There are four methods to delete cache in Redis: direct deletion (DEL command), batch deletion (KEYS UNLINK command), fuzzy deletion (SCAN UNLINK command) and time-based expiration (TTL).

How to delete the cache in Redis

Delete directly

Use theDELcommand to directly delete the cache of the specified key.

DEL key_name

Batch deletion

Use theKEYScommand to get the keys matching a specific pattern, and then use theUNLINKcommand to delete these in batches key.

For example: Delete all keys starting withproduct_*:

KEYS product_* UNLINK $(keyspace_keys ...)

Fuzzy delete

Use theSCANcommand to iterate over all keys and use thefnmatchmodule in a scripting language such as Python to match keys. Matching keys can be deleted using theUNLINKcommand.

Example: Delete all keys containing the stringuser_ID:

import redis import fnmatch r = redis.Redis() for key in r.scan_iter(): if fnmatch.fnmatch(key, "*user_ID*"): r.unlink(key)

Time-based expiration (TTL)

If a TTL is set for a key, the key will be automatically deleted upon expiration.

For example: Set the TTL of keyuser_infoto 10 minutes:

EXPIRE user_info 600

Notes

• Be careful with security when deleting cache as this may result in data loss.
• Use fuzzy delete with caution as it may accidentally delete other keys.
• Regularly clear caches that are no longer needed to optimize Redis performance.

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